Patent GB-630793-A (GB)
Title: Record changer
IPC: G11B17/16
Filed: 1946-11-21
Abstract: 630,793. Magazine gramophones. LINCOLN ENGINEERING CO. Nov. 21, 1946, No. 34523. Convention date, Nov. 21, 1945. [Class 40 (ii)] In a magazine gramophone operated by pneumatic means, records are transferred from the magazine 241, by an arm 229 carrying a suction pad 237, to an invertible turntable 143 which has a suction grip and is small enough in diameter to permit the reverse side of the record to be played after inversion of the turntable, means also being provided to release the record after playing into a drawer 637 below. Motive power to rotate the turntable and to maintain a vacuum in a suction manifold 51 is obtained by means of an electric motor 25 which drives a shaft 99 and lay-shafts 95 and 103 via gear-boxes 97 and 101 respectively. The shaft 99 is coupled by a belt 23 to an eccentric shaft 29, Fig. 3, which is connected by links 31 to bellows 43 which are consecutively exhausted to maintain a vacuum in the suction manifold 51. Lay-shaft 103 is coupled by belts 109 and 115 to cam-shafts 113 and 119, respectively, Fig. 6, through gear trains and clutches which are brought into operation when automatic operations take place. The camshafts 113 and 119 control the opening of valves in manifolds 445 and 569, Fig. 49, for the purpose of controlling suction supply to the various bellows by which the different automatic movements are made. The turntable 143 is supported on a hollow shaft 125, Fig. 18, which is suspended on arms 127, Fig. 4, rotatable in bearings 129. The turntable 143 is driven by a shaft 141 having a bevel-gear 155 which is coupled to one or other of spring-loaded bevelgears 157 and 163 on shaft 95. In the normal position of the turntable 143 coupling is made with the bevel-gear 157, but when inverted, coupling is made with bevel-gear 163. The turn-table 143 is inverted and reverted by means of pinions 177, 179 under the control of a rod 185 operated by bellows 199 and 201, Figs. 3 and 49. The arm 229 is traversed by means of a rod 277 and bellows 291 and 283, while the suction pad 237 is lifted and lowered by means of a rod 257 and bellows 265. The pick-up arm 309 is lifted and lowered by means of bellows 327, Figs. 7 and 49, which are supported on a bracket 323 secured to the pick-up arm support 313. The outward traverse of the pick-up arm 309 is effected by a link 397, Fig. 4, and a bellows 387, a lost-motion slot 395 being provided to permit the pick-up arm to traverse the record, and to be fed to the start of the groove by an arm 359, Fig. 11, under the control of a rod 367 and bellows 375. A wheel 385 on the end of the arm 359 comes into contact with the edge of the record 240 and ensures that the stylus is set down at the correct place. During the normal sequence of operations when it is required to play both sides of the records the drop-recording valve 507 is set as shown in Fig. 49. The first record to be played is placed upon the turn-table 143 whilst the remainder are stacked on the raised platform 14, the suction pad 237 being raised and lowered by hand while doing so. The electric motor is then switched on and the stylus of the pick-up placed manually in the start of the groove of the record on the turn-table 143. When the pickup reaches the end of the record, the rear end of the pick-up arm 309 comes into contact with a plunger 609, Fig. 11, of a valve 597, Fig. 49, which is thereby opened so that a bellows 429 operates a clutch, Figs. 19 and 20 (not shown), which causes the cam-shaft 113 controlling the valves in the manifold 445 to be rotated. During the first part of the rotation of the cam-shaft 113 the valve 461 is opened so that suction in clutch-bellows 429 is maintained during the first automatic cycle in which the pick-up arm 309 is returned and the turn-table 143 inverted, these motions being controlled by the sequential opening of the appropriate valves 465, 477, &c. in the manifold 445. These valves are opened and closed by cams 465, 477, &c. as illustrated in Figs. 23 to 33 inclusive (not shown). During the automatic operation described above the cams 465, 477, &c. perform part of a revolution, and when the stylus rests in the groove of the reverse side of the record, valve 461 closes and rotation of the cam-shaft 113 ceases. At the end of the reverse side of the record, valve 597 is again opened and the cam-shaft 113 completes its rotation, during which the pickup arm 309 is returned, the record released into the drawer 637, the turn-table 143 reverted, the next record placed thereon and the stylus fed into the start of the groove of the next record, after which the valve,461 again closes and the cam-shaft 113 comes to rest in its initial position ready for the next cycle. When there are no longer records on the turn-table 143 the wheel 385 on the arm 359 meets no resistance from the edge of a record and the arm 359 continues its inward traverse until a projection 641 at the rear end of the arm 359 comes into contact with an electric switch 643 and breaks the motor circuit, at which moment the cam-shaft 113 is in the original starting position, and is thereupon de-clutched. When it is desired to play only the top sides of the records, the drop-recording valve 507, Fig. 49, is pushed downward so that the lines 503 are disconnected from one another and the lines 519 connected together. The effect is to suspend the inward traverse of the arm 359 while the cam-shaft 113 is made to complete a full revolution by means of the valve 517 (hitherto ineffective), and clutch-bellows 429. During this part of the rotation of cam-shaft 113, the record is released from the inverted turn-table 143, the turn-table reverted and a fresh record placed thereon. During playing of any record it may be rejected by pressing the button 615 of a reject-valve 613, Fig. 49, which is connected in parallel with the sequence valve 597. When it is desired to repeat the playing of a record the repeater valve 471, Fig. 49, is pulled upwards. By this means the lines 617, 519 and 463 to the clutch-bellows 429 are rendered ineffective, and the operation of valves 597 or 613 serves to operate clutchbellows 430, which control a cam-shaft. 119 controlling the valves 571, 579, 583 and 587 on the manifold 569. By its use the operations of record-changing, turn-table inversion, record release and replacement are omitted. During functioning of the automatic mechanism, movement of the repeater valve 471 is prevented in either direction by the use of bellows 543 or 539 and intercepting rods 545 or 541 respectively. The drawer 637 which contains the used records is fitted with an electricallyoperated catch 647 which prevents the drawer being opened once the machine has been started, and is also fitted with a contact switch 645 so that the machine cannot be started until the drawer 637 is closed. The complete apparatus is housed in a bureau-like cabinet, Figs. 1 and 2 (not shown), in which separate compartments are provided for records and amplifying equipment.